As a society we have become dependent on satellite communications, but satellites fail with alarming frequency. Before the advent of satellites, long distance communications were carried out with high frequency (HF) radio transmissions. This lesson examines the factors that control long-distance radio communications, with an emphasis on refraction in the ionosphere, frequency selection, and the effects of solar radiation.

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kb3rdr 2019-02-16 18:27:27

Very nice, enjoyed the content and quiz.

englishp 2018-12-08 15:17:14

Great overview!

Weatherbyrd 2018-10-26 16:10:15

This was a good refresher for me since it has been many years since I was NCOIC of the Solar Observing Section of AESC at the Cheyenne Mountain Complex. It was good to refresh my memories. Also a good short course or introduction to Ionospheric Physics. Would refer others to visit the Space Weather modules that COMET has produced. Thanks!

Harshinator 2018-10-10 16:53:59

Tough stuff for a guy like myself, but enjoyed the lesson!

kk4bhs 2018-09-16 12:08:50

some is confusing but the videos are short enough I can play them again and usually understand enough.

This lesson was way over my head, never used any of this information before. Was very informative.

ke8jio 2018-09-02 17:52:26

It would be nice to have transcripts or .pfd files for future reference.

bemace 2018-08-20 21:42:51

Some very useful info for radio amateurs, but a couple esoteric topics are covered pretty briefly, which leads to memorization target than understanding

chipveres 2018-08-04 19:38:34

A good basic lesson in HF wave propagation. Watch out for the questions where you have to provide four answers to get one right.

Kiltedbiker 2018-08-03 07:37:11

Much of this information was new to me. My interest is piqued and I will be studying this more in depth.

wally.hunt 2018-07-17 18:05:46

Great lesson on the science of radio wave propagation.

Abo 2018-07-11 00:07:09

Great information for HF, has a lot of information that's in the General Exam.

gbennett 2018-07-01 12:19:26

I was a military radio operator focusing on HF work. Now I am a Ham radio operator helping to educate other hams about radio wave propagation. This lesson is by far the best at covering this topic without descending into deep mathematics to explain it all. Many thanks to the folks who put this lesson together!!Greg KC1CIC

aubrey_ainsworth 2018-06-30 06:35:49

kepplercs@gmail.com 2018-06-30 06:35:39

k2lyv 2018-06-29 15:14:15

Good solid background to understand HF prooagation. Should be oart of any serious ham's education

Tabsz1 2018-06-29 07:33:26

The information was presented well, albeit, slightly faster than I would have preferred, but I guess that's why there is a pause button :-)

tbonetoad 2018-06-29 00:53:23

The material took too long to load in and the lesson had too many interuptions

ham 2018-06-28 13:25:53

Good for every ham operator.

jbledsoe 2018-06-28 13:07:53

Great class.

sblanton3 2018-06-26 06:01:51

While every thing wants to be super high-tech, we will still need Radio communications in the future, at least for National Defense applications and back-up when the next massive solar flare takes out a few satellites.

jmngondo 2018-06-25 05:01:03

interesting topic and very informal.

Shawn Hughes 2018-06-24 17:28:24

As a radio operator and technician, this course enhanced greatly my understanding of HF radio operation, and helps me to better utilize space-based communication systems, as well. Highly recommend, but you may need to go through some sections more than once!

drrichard 2018-06-24 16:54:00

Having all the FCC licenses I thought I knew this subject well, but this course taught me a lot. It coherently tied atmospheric propagation to solar radiation and radio transmission. Rather than approaching this subject piecemeal, which is how most books do it, this little course showed the connections between natural phenomena and communications across the HF and VHF spectrum and through the layers of the ionosphere. This worked well.

nancynel 2018-06-21 16:18:42

Good online class, well worth the time it takes to complete

ea3eph 2018-06-21 15:30:44

I am a radio amateur and the theme of HF propagation is the most beautiful and interesting for me.

forcefrog 2018-06-20 14:03:19

The lesson greatly enhanced my overall understanding of propagation that will lead to better communications across the amateur radio bands and appropriate use of frequencies.

jgspears 2018-06-19 14:18:47

Excellent overview. My only wish is that there were more depth on some of the topics. Will have to use the great references.

WA3UFN 2018-06-19 12:47:45

Highly recommended, especially for amateur radio operators who may have recently obtained their license and those who are interested in adding to their understanding of the topic.

MARLOS 2018-06-19 12:11:26

Very useful explanations and visualizations.

WHH114 2018-06-19 09:56:49

Some of the sections need to enumerate the content so it can be summariezed and used effectively and memorized properly.

KA5OXA 2018-06-18 20:51:30

Once I was able to discern the start and stop portions of the lesson it made a great deal more sense. It was a good lesson.

KG7UNI 2018-06-18 16:02:27

Good Course

jeffrey clark 2018-06-18 11:55:36

nice study guide

majones1 2018-06-17 19:54:33

I am a new Radio Amateur who has been away from electronics/radio communications for 40 years. This gave a good understanding of the basics of Propagation, clearing up a few issues I was unsure of prior to this.

globebiz 2018-06-17 12:46:32

Another great propagation course!

jasmuz 2018-06-16 17:49:04

Great learning material!

OCS 2018-06-16 17:14:55

Frequently had to reverse and pause in order to read diagram. I didn't like the use of archaic units (miles) when quizing on height of layers.

philrolfe 2018-06-16 09:05:00

very interresting

2018-06-16 08:46:17

Very good graphics. Information too quick at times.

margothtc 2018-06-15 21:27:25

While I have a ham radio and physics background, I learned quite a bit by taking this course. The course pulls much information that I have been exposed to into a cohesive whole.

vipin kumar maurya 2018-06-15 19:05:22

It's very advantageous to everyone studying on atmosphere.

KF5MVP 2018-06-15 17:42:48

Helped me to better understand the principles of propagation.

ac8to 2018-06-15 17:23:56

Overall an excellent lesson. My personal preference would be for more material in a slideshow format and less in a video format, but this is not a big issue.

JDFx 2018-06-15 15:50:04

Excellent course. Improved my understanding of propagation and will be put to use in my amateur radio operations.

Ralph25 2018-06-12 16:31:15

love it

eshuman 2018-06-08 10:51:11

As a Radio Amateur it helps explain propagation in easy to understand terms. Great lesson

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